PHASE BUTTON?????

[brenda b]

COULD SOMEONE TELL ME WHAT THE PHASE BUTTON ON MY ACOUSTIC GUITAR IS FOR ? APPRECIATE ANY INFO. IVE BEEN PLAYING MY GUITAR FOR YEARS AND IT JUST OCCURED TO ME THAT I DON'T KNOW WHAT IT'S FOR . SO WHAT DOES IT DO? THANKS

[Scodiddly]

Hi Brenda, please turn off your capslock key.

 

The "phase" or "polarity" button ("polarity" is the correct word) changes the polarity of (usually) a mic relative to a pickup. So you've apparently got a system where a mic and a pickup are being mixed together. If the signals are "out of phase" or "have reversed polarity", the final sound might end up thin and wonky. So having the option to hit the button is kind of a nice feature. Basically just play around, decide which position sounds better, and leave it there. Sometimes you can kill feedback problems with that button, so maybe try it at each gig you play.

[seagullplayer77]

Phase occurs when a pair of channels (e.g. two microphones amplifying the same guitar) are out of sync. In your case, the phase button is likely designed to help keep your two pickups (probably a mic and a UST) in phase and sounding their best. If the two systems are out of sync, you'll probably hear a slight pulsating, almost like you've got a flanger hooked up to your guitar.

[jamesp]

[fingerpicker]

You can be "out of phase" in relation to where you are standing and where your speakers are. This is why there will be a phase switch even on preamps with one pickup source.

 

Basically each time you are ready to perform, press the phase switch. Whichever sound is more desirable keep it there for that gig.

 

In phase will have more warmer sound--more bass.

Out of phase can cut bass response--sometimes helping avoid feedback.

[Terry Allan Hall]

You can be "out of phase" in relation to where you are standing and where your speakers are. This is why there will be a phase switch even on preamps with one pickup source. Basically each time you are ready to perform, press the phase switch. Whichever sound is more desirable keep it there for that gig. In phase will have more warmer sound--more bass. Out of phase can cut bass response--sometimes helping avoid feedback.

 

[brenda b]

Wow, nice to know, as I have at times experienced feedback problems despite using a soundhole cover and proper placement of equipment. It's nice to know I have another option. Appreciate your responses....Thanx:wave:

[Jon Chappell]

 

Wow, nice to know, as I have at times experienced feedback problems despite using a soundhole cover and proper placement of equipment. It's nice to know I have another option. Appreciate your responses....Thanx:wave:

 

 

It's the thinner, weaker sound that will nullify feedback. So you shouldn't be using the phase switch to eliminate feedback as you're sacrificing tone and richness along with the feedback. Try other options first--different positions on stage (though you said you've tried this), an equalizer with notch filters, or even a dedicated feedback eliminator.

 

Phase vs. Polarity: It's called a "phase" switch, but Scodiddly is correct in saying that what the switch really does is reverse the polarity of the signal. But a signal whose polarity is reversed creates the same condition as one that's 90 degrees out of phase, so that's why it's not completely incorrect here (just misleading).

 

The same thing occurs on a three-pickup electric guitar when you run one of two adjacent pickups "out of phase" with the other to create a softer, more chorus-y sound. You're just reversing the polarity of one of the pickups--creating a weaker signal with more cancellations, but one that produces desired musical results in some situations.